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West Elk Mine
<br />sedimentation ponds MB-1 or MB-2R for treatment, if necessary, and is discharged into the
<br />receiving streams or to temporary storage in various sumps within the mine. The changed timing of
<br />these return flows to the receiving streams is of no practical consequence, because the inflows via
<br />fault systems far exceed the losses (or consumptive uses) to the North Fork. In addition, the mine
<br />inflows are a new, non-tributary source of contributions to the North Fork. Similazly, because
<br />losses within the mine are roughly 5 percent of the total inflow, the annual loss will be 1 acre foot or
<br />less. It is also important to recognize that at those times when inflows (other than those from the
<br />fault systems) to the mine are likely to be at their highest levels (during snowmelt runoff), water
<br />users in both basins should be satisfied rather than "tailing" for water.
<br />Streams
<br />Baseline data for streams in and adjacent to the permit area aze being obtained as presented in
<br />Section 2.04.7 and, more specifically, in Table 4 of Exhibit 71. Drainage basins and the resources
<br />monitored or proposed for monitoring aze shown on Map 34.
<br />Monitoring to deternrine the hydrologic consequences to streams is by seasonal measurements
<br />(three times per yeaz to correspond to the start of spring runoff, the peak spring runoff, and the fall
<br />low flow) of flow, pH, conductivity, and temperature aze taken. Seasonal samples aze also obtained
<br />from the Sylvester Gulch and North Fork sites for analysis of TDS Fe, Mn, and TSS. Annually
<br />during the second sampling (except for the North Fork which is during the third sampling}, MCC
<br />performs afull-suite laboratory analysis of water solids (TDS), total suspended solids (TSS),
<br />calcium, magnesium, sodium, SAR, hazdness, bicazbonate, chloride, nitrate/nitrite, phosphate (POZa
<br />as P), sulfate, iron (total & dissolved), manganese (total & dissolved), aluminum (dissolved) azsenic
<br />(total recoverable}, cadmium, copper, lead, mercury (total recoverable), molybdenum, selenium
<br />(total recoverable), and zinc.
<br />A seasonal, rather than quarterly or semi-annual water quality monitoring schedule was instituted
<br />for a variety of reasons. The primary reason for selecting seasonai sampling is that, in many
<br />instances, particularly streamflow and spring flows, these are the only periods of measurable flow.
<br />Most of the streams aze ephemeral or intermittent at best, and nearly all of the springs are ephemeral
<br />except in the wettest years. The nine years of baseline data cleazly indicate that there is no reason to
<br />attempt to sample these locations in the dead of winter. The adverse conditions encountered in the
<br />remote areas of the West Elk Mine lease azea severely hamper sampling procedures and influence
<br />the collection of meaningful data. As a result, by restricting sampling to the periods of flow and
<br />ensuring sample integrity, MCC will be able to provide meaningful data to the agency while
<br />reducing the costs associated with collecting unnecessary data or data that is not meaningful.
<br />MCC has selected the water quality parameters above and in Table 4 of Exhibit 71 for routine
<br />measurement because they aze most commonly associated with coal mining impact on water
<br />quality. Annual full-suite monitoring will allow MCC to identify possible mining-induced changes
<br />in water quality. Monitoring data, along with a discussion of any impacts observed or projected,
<br />will be provided in an Annual Hydrology Report to be submitted by Apri130 each year.
<br />i
<br />2.05-294 RevisedJwie 2005 PRIO; Rev. March 2006; Rev. May 2006 PRIO
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